Sensor system integrated with a glove

ABSTRACT

Sensor systems are described that are designed to be integrated with gloves for the human hand. An array of sensors detects forces associated with action of a hand in the glove, and associated circuitry generates corresponding control information that may be used to control a wide variety of processes and devices.

RELATED APPLICATION DATA

The present application is a non-provisional of and claims priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application No. 62/072,798 entitled Flexible Sensors and Applications filed on Oct. 30, 2014 (Attorney Docket No. BBOPP004P3). The present application is also a continuation-in-part of and claims priority under 35 U.S.C. 120 to U.S. patent application Ser. No. 14/671,821 entitled Flexible Sensors and Applications filed on Mar. 27, 2015 (Attorney Docket No. BBOPP004X2), which is a continuation-in-part of and claims priority under 35 U.S.C. 120 to U.S. patent application Ser. No. 14/299,976 entitled Piezoresistive Sensors and Applications filed Jun. 9, 2014 (Attorney Docket No. BBOPP004). The entire disclosure of each of the foregoing applications is incorporated herein by reference for all purposes.

BACKGROUND

Demand is rapidly rising for technologies that bridge the gap between computing devices and the physical world. These interfaces typically require some form of sensor technology that translates information from the physical domain to the digital domain. The “Internet of Things” contemplates the use of sensors in a virtually limitless range of applications, for many of which conventional sensor technology is not well suited.

SUMMARY

According to various implementations, sensors and applications of sensors are provided. According to some implementations, a sensor system includes a flexible substrate for alignment or integration with a portion of a glove. A plurality of conductive trace groups formed directly on the substrate at sensor locations correspond to at least some finger joints of a human hand. Each of the conductive trace groups includes two or more conductive traces. The resistance between the conductive traces in each of the conductive trace groups varies with force on piezoresistive material in contact with the conductive trace group. Circuitry is configured to receive a signal from each of the conductive trace groups and generate control information in response thereto. The control information represents the force on the piezoresistive material in contact with each of the conductive trace groups.

According to a particular class of implementations, the flexible substrate is a dielectric material, and the piezoresistive material is a plurality of patches. Each patch of piezoresistive material is in contact with a corresponding one of the conductive trace groups at the sensor locations. According to a more specific implementation, the dielectric material is a thermoplastic material, and the sensor system includes a second flexible substrate of the thermoplastic material. The flexible substrate on which the conductive trace groups are formed, the patches of piezoresistive material, and the second flexible substrate are thermally bonded together such that the patches of piezoresistive material are secured in contact with the corresponding conductive trace groups.

According to another class of implementations, the flexible substrate is the piezoresistive material which may be, for example, a piezoresistive fabric.

A further understanding of the nature and advantages of various implementations may be realized by reference to the remaining portions of the specification and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows examples of trace patterns that may be integrated with a flexible substrate.

FIG. 2 shows examples of different types of distortions to a flexible substrate.

FIG. 3 shows a particular implementation of a sensor array.

FIG. 4 is a simplified block diagram of sensor circuitry suitable for use with various implementations.

FIG. 5 shows examples of relationships among a piezoresistive substrate, conductive traces, and other conductive elements in one-sided and two-sided sensor implementations.

FIG. 6 shows another implementation of a sensor array.

FIG. 7 shows another implementation of a sensor array.

FIG. 8 shows an example of a cross-section of some of the components of a sensor system.

FIG. 9 shows an example of a sensor array integrated with a glove blank.

FIG. 10 shows another implementation of a sensor array.

FIG. 11 shows another implementation of a sensor array.

DETAILED DESCRIPTION

Sensors and sensor systems incorporating piezoresistive materials are described in this disclosure. In particular, sensor systems for integration with gloves for the human hand are described. Specific implementations are described herein including the best modes contemplated. Examples of these implementations are illustrated in the accompanying drawings. However, the scope of this disclosure is not limited to the described implementations. Rather, this disclosure is intended to cover alternatives, modifications, and equivalents of these implementations. In the following description, specific details are set forth in order to provide a thorough understanding of the described implementations. Some implementations may be practiced without some or all of these specific details. In addition, well known features may not have been described in detail to promote clarity.

Piezoresistive materials include any of a class of materials that exhibit a change in electrical resistance in response to mechanical force or pressure applied to the material. One class of sensor systems described herein includes conductive traces formed directly on or otherwise integrated with a flexible substrate of piezoresistive material, e.g., a piezoresistive fabric or other flexible material. Another class of sensor systems described herein includes conductive traces formed directly on or otherwise integrated with a flexible dielectric substrate with flexible piezoresistive material that is tightly integrated with the dielectric substrate and in contact with portions of the traces. When force or pressure is applied to such a sensor system, the resistance between traces connected by the piezoresistive material changes in a time-varying manner that is representative of the applied force. A signal representative of the magnitude of the applied force is generated based on the change in resistance. This signal is captured via the conductive traces (e.g., as a voltage or a current), digitized (e.g., via an analog-to-digital converter), processed (e.g., by an associated processor, controller, or suitable control circuitry), and mapped (e.g., by the associated processor, controller, or control circuitry) to a control function that may be used in conjunction with virtually any type of process, device, or system. The output signals from such sensor systems may also be used to detect a variety of distortions and/or deformations of the substrate(s) on which they are formed or with which they are integrated such as, for example, bends, stretches, torsions, rotations, etc.

Printing, screening, depositing, or otherwise forming conductive traces directly onto flexible substrates allows for the creation of a sensor or sensor array that fits any arbitrary shape or volume. The piezoresistive material on which the traces are formed or with which the traces are in contact may be any of a variety of woven and non-woven fabrics having piezoresistive properties. Implementations are also contemplated in which the piezoresistive material may be any of a variety of flexible, stretchable, or otherwise deformable materials (e.g., rubber, or a stretchable fabric such as spandex or open mesh fabrics) having piezoresistive properties. The conductive traces may be formed on the piezoresistive material or a flexible dielectric substrate using any of a variety of conductive inks or paints. Implementations are also contemplated in which the conductive traces are formed using any flexible conductive material that may be formed on a flexible substrate. It should therefore be understood that, while specific implementations are described with reference to specific materials and techniques, the scope of this disclosure is not so limited.

Both one-sided and two-side implementations are contemplated, e.g., conductive traces can be printed on one or both sides of flexible substrate. As will be understood, two-sided implementations may require some mechanism for connecting conductive traces on one side of the substrate to those on the other side. Some implementations use vias in which conductive ink or paint is flowed through the vias to establish the connections. Alternatively, metal vias or rivets may make connections through the flexible substrate.

Both single and double-sided implementations may use insulating materials formed over conductive traces. This allows for the stacking or layering of conductive traces and signal lines, e.g., to allow the routing of signal line to isolated structures in a manner analogous to the different layers of a printed circuit board.

Routing of signals on and off the flexible substrate may be achieved in a variety of ways. A particular class of implementations uses elastomeric connectors (e.g., ZEBRA® connectors) which alternate conductive and non-conductive rubber at a density typically an order of magnitude greater than the width of the conductive traces to which they connect (e.g., at the edge of the substrate). Alternatively, a circuit board (possibly made of a flexible material such as Kapton), or a bundle of conductors may be riveted to the substrate. The use of rivets may also provide mechanical reinforcement to the connection.

Matching conductive traces or pads on both the flexible substrate and a circuit board can be made to face each. A layer of conductive adhesive (e.g., a conductive epoxy such as Masterbond EP79 from Masterbond, Inc. of Hackensack, N.J.) can be applied to one of the surfaces and then mated to the other surface. The conductive traces or pads can also be held together with additional mechanical elements such as a plastic sonic weld or rivets. If conductive rivets are used to make the electrical connections to the conductive traces of the flexible substrate, the conductive adhesive may not be required. Conductive threads may also be used to connect the conductive traces of the flexible substrate to an external assembly.

According to a particular class of implementations, the piezoresistive material is a pressure sensitive fabric manufactured by Eeonyx, Inc., of Pinole, Calif. The fabric includes conductive particles that are polymerized to keep them suspended in the fabric. The base material is a polyester felt selected for uniformity in density and thickness as this promotes greater uniformity in conductivity of the finished piezoresistive fabric. That is, the mechanical uniformity of the base material results in a more even distribution of conductive particles when the slurry containing the conductive particles is introduced. The fabric may be woven. Alternatively, the fabric may be non-woven such as, for example, a calendared fabric e.g., fibers, bonded together by chemical, mechanical, heat or solvent treatment. For implementations in which conductive traces are formed on the piezoresistive fabric, calendared material presents a smoother outer surface which promotes more accurate screening of conductive inks than a non-calendared material.

The conductive particles in the fabric may be any of a wide variety of materials including, for example, silver, copper, gold, aluminum, carbon, etc. Some implementations may employ carbon graphenes that are formed to grip the fabric. Such materials may be fabricated using techniques described in U.S. Pat. No. 7,468,332 for Electroconductive Woven and Non-Woven Fabric issued on Dec. 23, 2008, the entire disclosure of which is incorporated herein by reference for all purposes. However, it should again be noted that any flexible material that exhibits a change in resistance or conductivity when force or pressure is applied to the material will be suitable for implementation of sensors as described herein.

According to a particular class of implementations, conductive traces having varying levels of conductivity are formed on flexible piezoresistive material or an adjacent flexible dielectric substrate using conductive silicone-based inks manufactured by, for example, E.I. du Pont de Nemours and Company (DuPont) of Wilmington, Del., and/or Creative Materials of Ayer, Mass. An example of a conductive ink suitable for implementing highly conductive traces for use with various implementations is product number 125-19 from Creative Materials, a flexible, high temperature, electrically conductive ink. Examples of conductive inks for implementing lower conductivity traces for use with various implementations are product numbers 7102 and 7105 from DuPont, both carbon conductive compositions. Examples of dielectric materials suitable for implementing insulators for use with various implementations are product numbers 5018 and 5036 from DuPont, a UV curable dielectric and an encapsulant, respectively. These inks are flexible and durable and can handle creasing, washing, etc. The degree of conductivity for different traces and applications is controlled by the amount or concentration of conductive particles (e.g., silver, copper, aluminum, carbon, etc.) suspended in the silicone. These inks can be screen printed or printed from an inkjet printer. Another class of implementations uses conductive paints (e.g., carbon particles mixed with paint) such as those that are commonly used for EMI shielding and ESD protection.

Examples of sensors and arrays of sensors that may be used with various implementations enabled by the present disclosure are described in U.S. patent application Ser. No. 14/299,976 entitled Piezoresistive Sensors and Applications filed on Jun. 9, 2014 (Attorney Docket No. BBOPP004), the entire disclosure of which is incorporated herein by reference for all purposes. However, it should be noted that implementations are contemplated that employ a variety of other suitable sensor technologies.

Forming sensors on flexible substrates enables numerous useful devices. Many of these devices employ such sensors to detect the occurrence of touch events, the force or pressure of touch events, the duration of touch events, the location of touch events, the direction of touch events, and/or the speed of motion of touch events. The output signals from such sensors may also be used to detect a variety of distortions and/or deformations of the substrate on which they are formed or with which they are integrated such as, for example, bends, stretches, torsions, rotations, etc. The information derived from such sensors may be used to effect a wide variety of controls and/or effects. Examples of distortions and/or deformations are described below with reference to the accompanying figures. As will be understood, the specific details described are merely examples for the purpose of illustrating the range of techniques enabled by this disclosure.

FIG. 1 shows an example of a sensor trace pattern 100 integrated with a flexible substrate 102. The flexible substrate may be a piezoresistive material or a dielectric material. In the latter case, a flexible piezoresistive material is tightly integrated with the dielectric material an in contact with the sensor trace pattern. Trace pattern 100 includes a pair of conductive traces, one of which (trace 104) provides a sensor signal to associated circuitry (not shown), and the other of which (trace 106) is connected to ground or a suitable reference. Some representative examples of other trace patterns 108-116 are shown. In some implementations, the traces of a trace pattern may be formed directly, e.g., by screening or printing, on the flexible substrate which might be, for example, a piezoresistive fabric. However, it should be noted that, among other things, the geometries of the sensor trace pattern(s), the number of traces associated with each sensor, the number, spacing, or arrangement of the sensors, the relationship of the sensors to the substrate, the number of layers or substrates, and the nature of the substrate(s) may vary considerably from application to application, and that the depicted configurations are merely examples for illustrative purposes.

FIG. 2 shows examples of different types of distortions to flexible substrate 102 that may be detected via sensor trace pattern 100. FIG. 2( a) shows substrate 102 in its non-distorted state. FIG. 2( b) shows a side view of substrate 102 bending; FIG. 2( c) shows substrate 102 stretching; FIG. 2( d) represents substrate 102 rotating relative to surrounding material; and FIG. 2( e) shows a side view of substrate 102 twisting due to an applied torque (i.e., torsion). In each of these scenarios, the resistance of the piezoresistive material in contact with trace pattern 100 changes in response to the applied force (e.g., goes down or up due to compression or increased separation of conductive particles in the piezoresistive material). This change (including its magnitude and time-varying nature) is detectable via sensor trace pattern 100 and associated electronics (not shown).

According to a particular implementation illustrated in FIG. 3, sensor trace patterns are formed on the stretchable material of a sensor glove 300 that may be used, for example, to translate a human's hand motions and the hand's interactions with the physical world into a virtual representation of the hand (or some other virtual object) and its interactions in a virtual environment. In another example, the hand's motions and interactions may be used to control a robotic hand or device in the physical world. The material on which the trace patterns are formed may be a flexible piezoresistive material or a flexible dielectric material. Again, in the latter case, a flexible piezoresistive material is tightly integrated with the flexible substrate on which the trace patterns are formed and in contact with the trace patterns at the various sensor locations (i.e., S1-S19).

As shown, trace patterns corresponding to some of the sensors (e.g., S1-S5 and S14-S18) are placed to coincide with various joints of the fingers (e.g., knuckles or finger joints) to capture distortion and/or deformation of the glove in response to bending and flexing of those joints. Other sensors (e.g., S6-S13 and S19) are placed to capture stretching of the glove, e.g., as occurs when the fingers of the hand are spread out. Other sensors (not shown) may also be placed on the palm of the glove and/or the tips of the fingers to detect bending and flexing forces as well as forces relating, for example, to touching, gripping, or otherwise coming into contact with objects or surfaces.

Portions of the conductive traces that are not intended to be part of a sensor (e.g., signal routing traces) may be shielded or insulated to reduce any unwanted contributions to the sensor signals. That is, the portions of the conductive traces that bring the drive and sense signals to and from the sensors may be insulated from the piezoresistive material using, for example, a dielectric or non-conducting material between the piezoresistive material and the conductive traces. According to some implementations in which the conductive traces are formed on a flexible dielectric material, isolated pieces of piezoresistive material may be selectively located at the respective sensor locations.

In the depicted implementation there are 19 sensors, S1-S19. Each of the sensors includes two adjacent traces, the respective patterns of which include extensions that alternate. See, for example, the magnified view of sensor S4. One of the traces 301 receives a drive signal; the other trace 302 transmits the sensor signal to associated sensor circuitry (not shown). The drive signal might be provided, for example, by connecting the trace (permanently or temporarily) to a voltage reference, a signal source that may include additional information in the drive signal, a GPIO (General Purpose Input Output) pin of an associated processor or controller, etc. And as shown in the example in FIG. 3, the sensor signal might be generated using a voltage divider in which one of the resistors of the divider includes the resistance between the two traces through the intervening piezoresistive material. The other resistor (represented by R1) might be included, for example, with the associated sensor circuitry. As the resistance of the piezoresistive material changes with applied force or pressure, the sensor signal also varies as a divided portion of the drive signal.

The sensors are energized (via the drive signals) and interrogated (via the sensor signals) to generate an output signal for each that is a representation of the force exerted on that sensor. As will also be appreciated, and depending on the application, implementations are contemplated having more or fewer sensors.

According to various implementations, different sets of sensors may be selectively energized and interrogated thereby reducing the number and overall area of traces on the substrate, as well as the required connections to sensor circuitry on an associated PCB (which may be positioned, for example, in cutout 322). For example, in the sensor system of FIG. 3, the 19 sensors are driven via 11 drive signal outputs from the sensor circuitry (not shown), and the sensor signals are received via 2 sensor signal inputs to the sensor circuitry; with 13 connections between the flexible substrate on which the conductive traces are formed and the PCB in cutout 322 as shown. The set of sensors providing sensor signals to one of the 2 sensor signal inputs (e.g., S6-S13 in one set and S1-S5 and S14-S19 in the other) may be energized in any suitable sequence or pattern such that any signal received on the corresponding sensor signal input can be correlated with the corresponding sensor drive signal by the sensor circuitry.

And because the sensor signals in this implementation are received by the sensor circuitry via two different sensor signal inputs, two sensors can be simultaneously energized as long as they are connected to different sensor signal inputs to the sensor circuitry. This allows for the sharing of drive signal lines. For example, in the implementation of FIG. 3, eight pairs of sensors share a common drive signal line, i.e., S2 and S8, S3 and S10, S4 and S12, S6 and S14, S7 and S15, S9 and S16, S11 and S17, and S13 and S19. The sharing of the common drive signal lines may be enabled by insulators which allow the conductive traces to cross, as well as locations at which the conductive traces simply diverge. Other suitable variations on this theme will be understood by those of skill in the art to be within the scope of this disclosure.

According to some implementations, a PCB may be connected to the conductive traces of the sensor array as described U.S. patent application Ser. No. 14/671,821 entitled Flexible Sensors and Applications filed on Mar. 27, 2015 (Attorney Docket No. BBOPP004X2), the entire disclosure of which is incorporated herein by reference for all purposes. According to other implementations, any of a variety of techniques may be employed to make such a connection including, for example, elastomeric connectors (e.g., ZEBRA® connectors) which alternate conductive and non-conductive rubber at a density typically an order of magnitude greater than the width of the conductive traces to which they connect (e.g., at the edge of the fabric). A variety of other suitable alternatives are available to those of skill in the art.

FIG. 4 is a simplified diagram of sensor circuitry that may be provided on a PCB for use with implementations described herein. For example, in the implementation described above with reference to FIG. 3, such sensor circuitry could be provided on a PCB in cutout 322 and connected to the conductive traces associated with sensors S1-S19. When force is applied to one of the sensors, a resulting signal (captured via the corresponding traces) is received and digitized (e.g., via multiplexer 402 and A-D converter 404) and may be processed locally (e.g., by processor 406) and/or transmitted to a connected device (e.g., via a Bluetooth or other wireless connection, or even via a USB connection). The sensors may be selectively energized by the sensor circuitry (e.g., under the control of processor 406 via D-A converter 408 and multiplexer 410) to effect the generation of the sensor signals. The C8051F380-GM controller (provided by Silicon Labs of Austin, Tex.) is an example of a processor suitable for use with various implementations.

In addition to transmission of data to and from a connected device, power may be provided to the sensor circuitry via a USB connection. Alternatively, systems that transmit data wirelessly (e.g., via Bluetooth) may provide power to the sensor circuitry using any of a variety of mechanisms and techniques including, for example, using one or more batteries, solar cells, and/or mechanisms that harvest mechanical energy. The LTC3588 (provided by Linear Technology Corporation of Milpitas, Calif.) is an example of an energy harvesting power supply that may be used with at least some of these diverse energy sources. Other suitable variations will be appreciated by those of skill in the art. And as will be appreciated, the sensor circuitry shown in FIG. 4 is merely an example. A wide range of sensor circuitry components, configurations, and functionalities are contemplated.

Both one-sided and two-side implementations are contemplated, e.g., conductive traces can be formed on one or both sides of a flexible substrate. As will be understood, two-sided implementations may require some mechanism for connecting conductive traces on one side of the substrate to those on the other side. Some implementations use vias in which conductive ink or paint is flowed through the vias to establish the connections. Alternatively or additionally, metal vias or rivets may make connections through the substrate. FIG. 5 illustrates the use of vias or rivets through the flexible substrate (e.g., configuration 502), and the use of insulating materials to insulate conductive traces from the substrate where the substrate is a piezoresistive material (e.g., configuration 504). Such mechanisms enable complex patterns of traces and routing of signals in a manner analogous to the different layers of a PCB.

For example, assuming an implementation in which the conductive traces are formed on piezoresistive material and referring again to FIG. 3, conductive traces that transmit signals to and from the sensors of glove 300 may be insulated from the underlying piezoresistive substrate by an insulating material. This is most clearly illustrated in the figure by insulators 304 and 306 that are associated with the drive and sense signal lines connected to sensor S4. In addition, sense signal lines from multiple sensors are connected to each other on the opposite side (not shown) of the material depicted in FIG. 3 through the use of vias at locations 310-318.

According to a particular implementation of a sensor glove and as shown in FIG. 6, sensor trace patterns (e.g., 601-604) may be placed in a roughly cylindrical configuration around the wrist to detect bending of the wrist in two dimensions (e.g., up, down, left, right). When all four sensors register a similar response, this could mean that the wrist is twisting. However, this configuration may not provide sufficient information to determine the direction of the twist. Therefore, according to a particular implementation, an outer cylinder 608 may be attached to an inner cylinder 610 with at least two stretch sensors (e.g., 612 and 614). By comparison of the outputs of these stretch sensors, the direction (e.g., 616) as well as the amount of the rotation can be captured.

FIG. 7 illustrates particular class of implementations of a sensor array 700 for use in a sensor glove in which conductive traces are formed on a flexible dielectric substrate 702. Operation of sensor array 700 is similar to operation of the sensor array of sensor glove 300 as described above. And it should be noted that the depicted configuration of traces might also be included in implementations in which the traces are formed on piezoresistive material.

According to a particular implementation, substrate 702 may be constructed from a thermoplastic polyurethane (TPU) material such as, for example, Products 3415 or 3914 from Bemis Associates Inc. of Shirley, Mass. The conductive traces may be screen printed on the substrate using a conductive flexible ink such as, for example, conductive silicone-based inks manufactured by E.I. du Pont de Nemours and Company (DuPont) of Wilmington, Del., or Creative Materials of Ayer, Mass. Patches of a piezoresistive material (e.g., the Eeonyx fabric discussed above) are placed in contact with the conductive traces at the locations of sensors S1-S14. See for example, piezoresistive patch 704 at sensor S4. A second substrate of the TPU material (not shown) is placed over array 700, and the assembly is heated to thermally bond the components together, fixing the piezoresistive patches in contact with their respective sensor traces.

The relationships of the components of this assembly may be understood with reference to FIG. 8 which shows a flexible substrate 802 on which a conductive trace 804 is formed. Piezoresistive material 806 is maintained in contact with trace 804 by a second flexible substrate 808. In the depicted example, substrates 802 and 808 are TPU substrates and trace 804 is a conductive ink that is screen printed on TPU substrate 802. According to a particular implementation, TPU substrate 802 has an adhesive-barrier-adhesive (ABA) structure that allows for the assembly to be thermally bonded (e.g., melted) to another substrate such as, for example, a fabric glove blank 900 as depicted in FIG. 9. The other TPU substrate 808 is shown an adhesive-barrier (AB) structure so that it only bonds to the assembly. However, implementations are contemplated in which this substrate has an ABA structure to enable thermal bonding on both sides of the assembly.

According to a more specific implementation, stiffeners (not shown) may be placed in alignment with at least some of the piezoresistive patches and the corresponding trace patterns for the purpose of amplifying the signals generated by the corresponding sensors, e.g., by the force of the stiffener resisting bending of a knuckle and compressing the piezoresistive material. A stiffener might be a plastic film (e.g., polyethylene terephthalate or PET). Alternatively, a stiffener may be another piece of fabric. As yet another alternative, a stiffening material such as DuPont 5036 Dielectric ink may be silk-screened or printed on one of the components of the stack. As will be appreciated, stiffeners may be inserted at any point in the stack of materials (e.g., as depicted in FIG. 8) as long as the electrical connection between the conductive traces and the piezoresistive material is not unduly degraded.

Referring back to FIG. 7, a stiffener 706 (e.g., of PET or other suitable material) may be adhered to substrate 702 near the terminations of the conductive traces to allow for the insertion of the assembly into a connector 708 (see the exploded view in the lower right hand corner of the drawing). As will be appreciated, with stiffener 706 and the appropriate conductor spacing, this configuration allows for connection of sensor array 700 to any of a wide variety of industry standard connectors. According to a particular implementation, connector 708 is a Molex ZIF flat flex connector such as, for example, the Molex connector 52207-2860 (a 28 position connector) or the Molex connector 0522710869 (an 8 position connector as shown in FIG. 11).

As discussed above, sensor glove implementations are contemplated in which sensors are placed on the palm of the glove and/or the tips of the fingers to detect, for example, touching, gripping, or otherwise coming into contact with objects or surfaces. An example of how such a sensor might be integrated with an array is shown in FIG. 10. In the depicted example, flexible substrate 1002 extends beyond sensor S4 and includes a tab 1004 on which the conductive traces of sensor S15 are formed. Tab 1004 can be wrapped around inside the glove (as indicated by the arrow) so that it coincides with the fingertip of the glove. Thus, any forces acting on the fingertip of the glove (e.g., by virtue of the fingertip coming into contact with a surface) will be detected by sensor S15. As will be appreciated, such sensors may be integrated with a sensor array for the back of the hand as shown in FIG. 10. Alternatively, such sensors may be implemented as separate array for the palm and fingertips.

FIG. 11 shows an alternative design for a sensor array 1100 for use in a sensor glove which includes only four elongated sensors; S1-S3 for the three middle fingers, and S4 for the thumb. As will be appreciated, this simpler design may be easier and/or cheaper to manufacture and may be sufficient or even more well-suited for some applications than the designs described above with reference to FIGS. 3 and 7. Nevertheless, sensor array 1100 operates similarly to the sensor arrays described and may be constructed using either approach. According to a particular implementation, substrate 1102 is constructed from a TPU material and the conductive traces are screen printed on substrate 1102 using a conductive flexible ink as described above with reference to FIGS. 7 and 8. Patches of a piezoresistive material (e.g., the Eeonyx fabric discussed above) are placed in contact with the conductive traces at the locations of sensors S1-S4. See for example, piezoresistive patch 1104 at sensor S3. A second substrate of the TPU material (not shown) is placed over array 1100, and the assembly is heated to thermally bond the components together, fixing the piezoresistive patches in contact with their respective sensor traces.

As with sensor array 700, a stiffener (not shown) may be adhered to substrate 1102 near the terminations of the conductive traces to allow for the insertion of the assembly into a connector 1108. As discussed above, use of the stiffener allows for connection of sensor array 1100 to any of a wide variety of industry standard connectors including, for example, the Molex connector 0522710869. Also as discussed above with reference to sensor array 700, stiffeners (not shown) may be placed in alignment with at least some of the piezoresistive patches and the corresponding trace patterns of sensor array 1100 for the purpose of amplifying the signals generated by the corresponding sensors.

As should be appreciated with reference to the foregoing description, the applications for sensor gloves enabled by the present disclosure are numerous and diverse. As mentioned above, the action of a human hand in such a sensor glove may be translated to control systems, devices, and processes in both the real and virtual worlds. Using a sensor glove, a human can interact with objects in a virtual space, having utility in video and online gaming, as well as educational and artistic applications. For example, a sensor glove may be used to simulate a surgical procedure, playing of a virtual musical instrument, conducting of a virtual orchestra, painting of a virtual work of art, etc. Translation of the movements of a human hand into the virtual world could support more realistic computer aided animation. Industrial applications might include remote control of manufacturing apparatus or robotics handling hazardous materials. As will be appreciated from the diversity of these examples, the range of applications is virtually limitless. The scope of this disclosure should therefore not be limited by reference to specific applications.

It will be understood by those skilled in the art that changes in the form and details of the implementations described herein may be made without departing from the scope of this disclosure. In addition, although various advantages and aspects may have been described with reference to particular implementations, the scope of this disclosure should not be limited by reference to such advantages and aspects. 

What is claimed is:
 1. A sensor system, comprising: a flexible substrate for alignment or integration with a portion of a glove; a plurality of conductive trace groups formed directly on the substrate at sensor locations corresponding to at least some finger joints of a human hand, each of the conductive trace groups including two or more conductive traces, wherein resistance between the conductive traces in each of the conductive trace groups varies with force on piezoresistive material in contact with the conductive trace group; and circuitry configured to receive a signal from each of the conductive trace groups and generate control information in response thereto, the control information representing the force on the piezoresistive material in contact with each of the conductive trace groups.
 2. The sensor system of claim 1, wherein the flexible substrate comprises a dielectric material, and wherein the piezoresistive material comprises a plurality of patches, each patch of piezoresistive material being in contact with a corresponding one of the conductive trace groups at the sensor locations.
 3. The sensor system of claim 2, wherein the dielectric material comprises a thermoplastic material, the sensor system further comprising a second flexible substrate of the thermoplastic material, wherein the flexible substrate on which the conductive trace groups are formed, the patches of piezoresistive material, and the second flexible substrate are thermally bonded together such that the patches of piezoresistive material are secured in contact with the corresponding conductive trace groups.
 4. The sensor system of claim 1, wherein the flexible substrate is the piezoresistive material.
 5. The sensor system of claim 4, wherein the piezoresistive material is a fabric.
 6. The sensor system of claim 1, wherein the conductive traces comprise conductive ink printed on the flexible substrate.
 7. The sensor system of claim 6, wherein the conductive ink comprises an elastomeric ink having conductive particles suspended therein.
 8. The sensor system of claim 1, wherein the conductive traces comprise conductive paint deposited on the flexible substrate.
 9. The sensor system of claim 1, wherein a subset of the conductive trace groups is configured to sense force caused by stretching of the glove in response to spreading apart of fingers of the human hand.
 10. The sensor system of claim 1, wherein a subset of the conductive trace groups is configured to sense force caused by flexing of a wrist associated with the human hand.
 11. The sensor system of claim 1, wherein a subset of the conductive trace groups is positioned to coincide with a palm of the human hand.
 12. The sensor system of claim 1, wherein a subset of the conductive trace groups is positioned to coincide with one or more of the fingertips of the human hand.
 13. The sensor system of claim 1, wherein the control information is configured for use by a computing device to control a virtual hand in a virtual environment.
 14. The sensor system of claim 1, wherein the control information is configured for use by an electronic system to control a robotic device.
 15. The sensor system of claim 1, wherein the conductive traces of the conductive trace groups terminate at an edge of the flexible substrate, the sensor system further comprising a stiffener coupled to the flexible substrate at the edge of the flexible substrate, the stiffener providing rigidity of the flexible substrate to facilitate insertion of the edge of the flexible substrate into a connector for routing of the signals to and from the sensor system.
 16. The sensor system of claim 1, further comprising a plurality of stiffeners, each of the stiffeners being positioned adjacent a corresponding one of the sensor locations. 